This invention relates to the field of electronic computers and communication systems in combination. It is of a type which will prevent the unauthorized use of the communication system unless and until an appropriate code sequence is entered. Once the combination or code has been properly entered, the computer enables the user to select or change the channel (frequency) on which the communication proceeds. This instrument is particularly useful for mobile communication transmitter/receivers commonly referred to as citizen band (CB) radios.
In the past, there have been a variety of devices to prevent unauthorized use of communication systems. These devices have uniformly failed to adequately deter unauthorized use of such systems.
While these devices have included a lock, the lock has not included structures herein provided to control the time element and number of trials for arriving at the right combination by unauthorized persons. Moreover, additional control over other operating characteristics such as the transmitter frequency has not been included in prior art systems.